At present, with the continuous development of electronic technologies, there are more and more electronic devices that can be configured to photograph, for example, a mobile phone, a digital camera, and a tablet computer. Using a mobile phone as an example, at present, most mobile phones are equipped with a touch screen and a photographing button; when the mobile phone is in a photographing mode, the touch screen may display in real time a preview image for reference to a user; and after selecting a target to photograph, the user may perform a photographing operation by tapping the photographing button.
However, when the user needs to take a selfie by using a rear camera or needs to photograph by raising the mobile phone high above the head top (during photographing in accident onlookers, car exhibition, music concerts, or model photographing), a problem easily occurs that the user cannot tap or even cannot find the photographing button. Moreover, as the size of a smart phone increases continuously, a user cannot conveniently tap a photographing button to start a shutter; in particular, tapping a photographing button becomes harder for a user having small hands or a user that wants to complete a photographing operation with one hand.
At present, a technical solution to the foregoing defect is to set a touch screen photographing function in a photographing device of a mobile phone, where photographing is performed by tapping a screen after the touch screen photographing function is opened in settings. As shown in a schematic diagram of a photographing device in the existing technology in a set state in FIG. 1, a touch screen 11 and a setting button 12 are included. A user may open a setting interface by pressing the setting button 12, so that a touch screen photographing function key 121 and other functional keys 122 are displayed. However, in the technical solution, the user is required to tap the setting button to select the touch screen photographing function, photographing by tapping a screen easily causes an unintended operation, and the touch screen photographing function conflicts with other functions of the photographing device, for example, when the touch screen photographing function key 121 is in a selected state, some of the other functional keys 122 (for example, an autofocus functional key) is inoperable.